Search results for "Computer Science Application"
showing 10 items of 3998 documents
Lagrangian finite element modelling of dam–fluid interaction: Accurate absorbing boundary conditions
2007
The dynamic dam-fluid interaction is considered via a Lagrangian approach, based on a fluid finite element (FE) model under the assumption of small displacement and inviscid fluid. The fluid domain is discretized by enhanced displacement-based finite elements, which can be considered an evolution of those derived from the pioneering works of Bathe and Hahn [Bathe KJ, Hahn WF. On transient analysis of fluid-structure system. Comp Struct 1979;10:383-93] and of Wilson and Khalvati [Wilson EL, Khalvati M. Finite element for the dynamic analysis of fluid-solid system. Int J Numer Methods Eng 1983;19:1657-68]. The irrotational condition for inviscid fluids is imposed by the penalty method and con…
Bending stress fields in composite laminate beams by a boundary integral formulation
1999
Abstract The elasticity of a composite laminate under bending loads is approached through a boundary integral formulation and solved by the boundary element method. The integral equations governing the behaviour of each layer within the laminate, are deduced using the reciprocity theorem. Exact analytical singular solutions of the generalized orthotropic elasticity, i.e. the fundamental solutions of the problem, are employed as the kernels of the integral equation. The formulation does not make any assumption as to the nature of the elastic response and it allows consideration of general section geometries and stacking sequences. The solution is obtained through the enforcement of the inter…
Dynamic response of beams excited by moving oscillators: Approximate analytical solutions for general boundary conditions
2023
In this paper, the dynamic response of an Euler-Bernoulli beam with general boundary conditions (BCs) and subject to a moving oscillator is examined. Notably, novel approximate closed-form expressions are determined for the vertical responses of both the beam and the moving oscillator, specifically considering the effect of damping in these systems, commonly omitted in standard approaches in the literature. In this regard, a modal superposition procedure is adopted and combined with an appropriate expansion-based approach of the dynamic response of the system, which naturally arises considering the oscillator-beam mass ratio to be reasonably small. Further, general boundary conditions are t…
A four-node MITC finite element for magneto-electro-elastic multilayered plates
2013
An isoparametric four-node finite element for multilayered magneto-electro-elastic plates analysis is presented. It is based on an equivalent single-layer model, which assumes the first order shear deformation theory and quasi-static behavior for the electric and magnetic fields. First, the electro-magnetic state of the plate is determined in terms of the mechanical primary variables, namely the generalized displacements, by solving the strong form of the magneto-electric governing equations coupled with the electro-magnetic interface continuity conditions and the external boundary conditions. In turn, this result is used into the layers constitutive law to infer the equivalent single-layer…
Fluid-structure interaction approach with smoothed particle hydrodynamics and particle-spring systems
2022
This paper presents a novel three-dimensional fluid-structure interaction (FSI) approach, where the meshless smoothed particle hydrodynamics (SPH) method is used to simulate the motion of incompressible fluid flows, whilst structures are represented by a simplified approach based on particle-spring systems. The proposed FSI technique allows to use independent spatial-temporal resolutions for the fluid and structural computational domains. The particle-spring elastic constants are calibrated and relationships with the mechanical material properties, Young's modulus and Poisson's ratio, are determined. Fluid and structure computational domains are separated by interfaces made of triangular el…
An integral framework for computational thermo-elastic homogenization of polycrystalline materials
2023
A grain scale framework for thermo-elastic analysis and computational homogenization of polycrystalline materials is proposed. The morphology of crystal aggregates is represented employing Voronoi tessellations, which retain the main statistical features of polycrystalline materials. The behaviour of the individual grains is modelled starting from an integral representation for anisotropic thermo-elasticity, which is numerically addressed through a dual reciprocity boundary element method. The integrity of the aggregate is enforced through suitable intergranular thermo-elastic continuity conditions. By virtue of the features of the underlying formulation, the polycrystalline thermo-elastic …
The Impact of Internet and Social Media Use on Well-Being
2021
The present research examines the longitudinal average impact of frequency of use of Internet and social networking sites (SNS) on subjective well-being of adolescents in Germany. Based on five-wave panel data that cover a period of nine years, we disentangle between-person and within-person effects of media use on depressive symptomatology and life satisfaction as indicators of subjective well-being. Additionally, we control for confounders such as TV use, self-esteem, and satisfaction with friends. We found that frequency of Internet use in general and use of SNS in particular is not substantially related subjective well-being. The explanatory power of general Internet use or SNS use to p…
Towards farm-level health management of offshore wind farms for maintenance improvements
2015
This paper studies a conceptual architecture for health management of offshore wind farms. To this aim, various necessary enablers of a health management sys- tem are presented to improve reliability and availability while optimizing maintenance costs. The main focus lies on improving existing condition monitoring systems based on concepts of condition-based maintenance and relia- bility centered maintenance. A brief review of the rel- evant state-of-the-art is presented and gaps to be filled towards realization of such health management system are discussed.
Digital communication and collaboration in lower secondary school
2021
This article investigates factors influencing teachers in secondary school when they plan for pupils’ use of digital tools for collaboration and communication. Six social studies teachers in Oslo were interviewed about how they facilitate digital collaboration and communication. The results demonstrate that teachers facilitate this to a certain extent, both in the form of pupils’ co-writing and sharing files with each other. However, there is little communication between pupils by means of digital tools as an integrated part of the teaching. None of the teachers mentioned communication using digital tools as part of basic competence without being directly asked about it. Based on the analys…
Promoting Surgical Residents’ Basic Skills via the Design and Implementation of a Simulation Training Tool
2019
Background. Surgical training in authentic work environments needs guidance practices, including simulation training within a competence-based framework. The use of simulators may actually have negative effects on professional learning if there is a lack of competence-based goals, tools, and guidance, integrated with work practices, and applied by trainers. Intervention. We designed simulation training tools to promote the surgical residents’ abilities to perform competently in basic surgical skills. Our educational and surgical team worked together and (i) specified the goals for the tasks, (ii) specified the skills to be achieved, (iii) and analyzed the learning outcomes. The assumption …